X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/b6fbf22d63de88b77d79cd0b1d2337e589cac6d7..fd4c285cd86a1c06acaa34c33cb898c057208ec5:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 460b1bfab..bc34d65b8 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -45,7 +45,7 @@ . Update the Copyright year (only) when changing content. . ///////////////////////////////////////////////////////////////////////////// -.set previousversion "4.84" +.set previousversion "4.85" .include ./local_params .set ACL "access control lists (ACLs)" @@ -1985,10 +1985,9 @@ Two different types of DNS record for handling IPv6 addresses have been defined. AAAA records (analogous to A records for IPv4) are in use, and are currently seen as the mainstream. Another record type called A6 was proposed as better than AAAA because it had more flexibility. However, it was felt to be -over-complex, and its status was reduced to &"experimental"&. It is not known -if anyone is actually using A6 records. Exim has support for A6 records, but -this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The -support has not been tested for some time. +over-complex, and its status was reduced to &"experimental"&. Exim used to +have a compile option for including A6 record support but this has now been +withdrawn. @@ -3811,11 +3810,13 @@ This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option. It signifies that the connection to the remote host has been authenticated. +.new .vitem &%-MCD%& .oindex "&%-MCD%&" This option is not intended for use by external callers. It is used internally by Exim in conjunction with the &%-MC%& option. It signifies that the remote host supports the ESMTP &_DSN_& extension. +.wen .vitem &%-MCP%& .oindex "&%-MCP%&" @@ -4646,6 +4647,13 @@ this option. .oindex "&%-X%&" This option is interpreted by Sendmail to cause debug information to be sent to the named file. It is ignored by Exim. + +.vitem &%-z%&&~<&'log-line'&> +.oindex "&%-z%&" +This option writes its argument to Exim's logfile. +Use is restricted to administrators; the intent is for operational notes. +Quotes should be used to maintain a multi-word item as a single argument, +under most shells. .endlist .ecindex IIDclo1 @@ -6871,8 +6879,8 @@ is used on its own as the result. If the lookup does not succeed, the &<>& for an explanation of what this means. The supported DNS record types are A, CNAME, MX, NS, PTR, SPF, SRV, TLSA and TXT, -and, when Exim is compiled with IPv6 support, AAAA (and A6 if that is also -configured). If no type is given, TXT is assumed. When the type is PTR, +and, when Exim is compiled with IPv6 support, AAAA. +If no type is given, TXT is assumed. When the type is PTR, the data can be an IP address, written as normal; inversion and the addition of &%in-addr.arpa%& or &%ip6.arpa%& happens automatically. For example: .code @@ -6881,8 +6889,7 @@ ${lookup dnsdb{ptr=192.168.4.5}{$value}fail} If the data for a PTR record is not a syntactically valid IP address, it is not altered and nothing is added. -For any record type, if multiple records are found (or, for A6 lookups, if a -single record leads to multiple addresses), the data is returned as a +For any record type, if multiple records are found, the data is returned as a concatenation, with newline as the default separator. The order, of course, depends on the DNS resolver. You can specify a different separator character between multiple records by putting a right angle-bracket followed immediately @@ -7004,7 +7011,7 @@ The authorization code can be &"Y"& for yes, &"N"& for no, &"X"& for explicit authorization required but absent, or &"?"& for unknown. .cindex "A+" "in &(dnsdb)& lookup" -The pseudo-type A+ performs an A6 lookup (if configured) followed by an AAAA +The pseudo-type A+ performs an AAAA and then an A lookup. All results are returned; defer processing (see below) is handled separately for each lookup. Example: .code @@ -9727,7 +9734,7 @@ ${sort{3:2:1:4}{<}{$item}} .endd sorts a list of numbers, and .code -${sort {$lookup dnsdb{>:,,mx=example.com}} {<} {${listextract{1}{<,$item}}}} +${sort {${lookup dnsdb{>:,,mx=example.com}}} {<} {${listextract{1}{<,$item}}}} .endd will sort an MX lookup into priority order. @@ -11260,6 +11267,7 @@ The building process for Exim keeps a count of the number of times it has been compiled. This serves to distinguish different compilations of the same version of the program. +.new .vitem &$config_dir$& .vindex "&$config_dir$&" The directory name of the main configuration file. That is, the content of @@ -11270,6 +11278,7 @@ contain the trailing slash. If &$config_file$& does not contain a slash, .vitem &$config_file$& .vindex "&$config_file$&" The name of the main configuration file Exim is using. +.wen .vitem &$demime_errorlevel$& .vindex "&$demime_errorlevel$&" @@ -11378,12 +11387,14 @@ This variable contains the path to the Exim binary. .vindex "&$exim_uid$&" This variable contains the numerical value of the Exim user id. +.new .vitem &$exim_version$& .vindex "&$exim_uid$&" This variable contains the version string of the Exim build. The first character is a major version number, currently 4. Then after a dot, the next group of digits is a minor version number. There may be other characters following the minor version. +.wen .vitem &$found_extension$& .vindex "&$found_extension$&" @@ -12438,6 +12449,8 @@ inbound connection when the message was received. It is only useful as the argument of a &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, or a &%def%& condition. +If certificate verification fails it may refer to a failing chain element +which is not the leaf. .vitem &$tls_out_ourcert$& .vindex "&$tls_out_ourcert$&" @@ -12452,6 +12465,8 @@ This variable refers to the certificate presented by the peer of an outbound connection. It is only useful as the argument of a &%certextract%& expansion item, &%md5%&, &%sha1%& or &%sha256%& operator, or a &%def%& condition. +If certificate verification fails it may refer to a failing chain element +which is not the leaf. .vitem &$tls_in_certificate_verified$& .vindex "&$tls_in_certificate_verified$&" @@ -12515,6 +12530,8 @@ When a message is received from a remote host over an encrypted SMTP connection, and Exim is configured to request a certificate from the client, the value of the Distinguished Name of the certificate is made available in the &$tls_in_peerdn$& during subsequent processing. +If certificate verification fails it may refer to a failing chain element +which is not the leaf. The deprecated &$tls_peerdn$& variable refers to the inbound side except when used in the context of an outbound SMTP delivery, when it refers to @@ -12526,6 +12543,8 @@ When a message is being delivered to a remote host over an encrypted SMTP connection, and Exim is configured to request a certificate from the server, the value of the Distinguished Name of the certificate is made available in the &$tls_out_peerdn$& during subsequent processing. +If certificate verification fails it may refer to a failing chain element +which is not the leaf. .vitem &$tls_in_sni$& .vindex "&$tls_in_sni$&" @@ -13269,6 +13288,7 @@ listed in more than one group. .row &%acl_smtp_mail%& "ACL for MAIL" .row &%acl_smtp_mailauth%& "ACL for AUTH on MAIL command" .row &%acl_smtp_mime%& "ACL for MIME parts" +.row &%acl_smtp_notquit%& "ACL for non-QUIT terminations" .row &%acl_smtp_predata%& "ACL for start of data" .row &%acl_smtp_quit%& "ACL for QUIT" .row &%acl_smtp_rcpt%& "ACL for RCPT" @@ -13571,11 +13591,13 @@ This option defines the ACL that is run after an SMTP DATA command has been processed and the message itself has been received, but before the final acknowledgment is sent. See chapter &<>& for further details. +.new .option acl_smtp_data_prdr main string&!! accept .cindex "PRDR" "ACL for" .cindex "DATA" "PRDR ACL for" .cindex "&ACL;" "PRDR-related" .cindex "&ACL;" "per-user data processing" +.wen This option defines the ACL that, if the PRDR feature has been negotiated, is run for each recipient after an SMTP DATA command has been @@ -13616,6 +13638,12 @@ This option is available when Exim is built with the content-scanning extension. It defines the ACL that is run for each MIME part in a message. See section &<>& for details. +.option acl_smtp_notquit main string&!! unset +.cindex "not-QUIT, ACL for" +This option defines the ACL that is run when an SMTP session +ends without a QUIT command being received. +See chapter &<>& for further details. + .option acl_smtp_predata main string&!! unset This option defines the ACL that is run when an SMTP DATA command is received, before the message itself is received. See chapter &<>& for @@ -14157,6 +14185,7 @@ This is an obsolete option that is now a no-op. It used to affect the way Exim handled CR and LF characters in incoming messages. What happens now is described in section &<>&. +.new .option dsn_advertise_hosts main "host list&!!" unset .cindex "bounce messages" "success" .cindex "DSN" "success" @@ -14168,6 +14197,7 @@ and RET and ORCPT options on MAIL FROM commands. A NOTIFY=SUCCESS option requests success-DSN messages. A NOTIFY= option with no argument requests that no delay or failure DSNs are sent. +.wen .option dsn_from main "string&!!" "see below" .cindex "&'From:'& header line" "in bounces" @@ -15661,6 +15691,7 @@ the time of delivery. They are normally used only for final local deliveries. This option is an obsolete synonym for &%bounce_return_size_limit%&. +.new .option rfc1413_hosts main "host list&!!" @[] .cindex "RFC 1413" .cindex "host" "for RFC 1413 calls" @@ -15668,8 +15699,11 @@ RFC 1413 identification calls are made to any client host which matches an item in the list. The default value specifies just this host, being any local interface for the system. +.wen +.new .option rfc1413_query_timeout main time 0s +.wen .cindex "RFC 1413" "query timeout" .cindex "timeout" "for RFC 1413 call" This sets the timeout on RFC 1413 identification calls. If it is set to zero, @@ -16063,7 +16097,7 @@ See &%smtp_ratelimit_hosts%& above. See &%smtp_ratelimit_hosts%& above. -.option smtp_receive_timeout main time 5m +.option smtp_receive_timeout main time&!! 5m .cindex "timeout" "for SMTP input" .cindex "SMTP" "input timeout" This sets a timeout value for SMTP reception. It applies to all forms of SMTP @@ -16078,6 +16112,10 @@ SMTP data timeout on connection from... The former means that Exim was expecting to read an SMTP command; the latter means that it was in the DATA phase, reading the contents of a message. +If the first character of the option is a &"$"& the option is +expanded before use and may depend on +&$sender_host_name$&, &$sender_host_address$& and &$sender_host_port$&. + .oindex "&%-os%&" The value set by this option can be overridden by the @@ -16517,6 +16555,7 @@ preference order of the available ciphers. Details are given in sections See &%tls_verify_hosts%& below. +.new .option tls_verify_certificates main string&!! system .cindex "TLS" "client certificate verification" .cindex "certificate" "verification of client" @@ -16539,11 +16578,7 @@ With OpenSSL the certificates specified explicitly either by file or directory are added to those given by the system default location. - -With OpenSSL the certificates specified -explicitly -either by file or directory -are added to those given by the system default location. +.wen These certificates should be for the certificate authorities trusted, rather than the public cert of individual clients. With both OpenSSL and GnuTLS, if @@ -16983,6 +17018,25 @@ or for any deliveries caused by this router. You should not set this option unless you really, really know what you are doing. See also the generic transport option of the same name. +.option dnssec_request_domains routers "domain list&!!" unset +.cindex "MX record" "security" +.cindex "DNSSEC" "MX lookup" +.cindex "security" "MX lookup" +.cindex "DNS" "DNSSEC" +DNS lookups for domains matching &%dnssec_request_domains%& will be done with +the dnssec request bit set. +This applies to all of the SRV, MX, AAAA, A lookup sequence. + +.option dnssec_require_domains routers "domain list&!!" unset +.cindex "MX record" "security" +.cindex "DNSSEC" "MX lookup" +.cindex "security" "MX lookup" +.cindex "DNS" "DNSSEC" +DNS lookups for domains matching &%dnssec_request_domains%& will be done with +the dnssec request bit set. Any returns not having the Authenticated Data bit +(AD bit) set wil be ignored and logged as a host-lookup failure. +This applies to all of the SRV, MX, AAAA, A lookup sequence. + .option domains routers&!? "domain list&!!" unset .cindex "router" "restricting to specific domains" @@ -17000,6 +17054,7 @@ This option must always be set. It specifies which of the available routers is to be used. +.new .option dsn_lasthop routers boolean false .cindex "DSN" "success" .cindex "Delivery Status Notification" "success" @@ -17007,6 +17062,7 @@ If this option is set true, and extended DSN (RFC3461) processing is in effect, Exim will not pass on DSN requests to downstream DSN-aware hosts but will instead send a success DSN as if the next hop does not support DSN. Not effective on redirect routers. +.wen @@ -17130,7 +17186,10 @@ and the discussion in chapter &<>&. .option headers_add routers list&!! unset .cindex "header lines" "adding" .cindex "router" "adding header lines" -This option specifies a list of text headers, newline-separated, +This option specifies a list of text headers, +.new +newline-separated (by default, changeable in the usual way), +.wen that is associated with any addresses that are accepted by the router. Each item is separately expanded, at routing time. However, this option has no effect when an address is just being verified. The way in which @@ -17167,7 +17226,10 @@ avoided. The &%repeat_use%& option of the &%redirect%& router may be of help. .option headers_remove routers list&!! unset .cindex "header lines" "removing" .cindex "router" "removing header lines" -This option specifies a list of text headers, colon-separated, +This option specifies a list of text headers, +.new +colon-separated (by default, changeable in the usual way), +.wen that is associated with any addresses that are accepted by the router. Each item is separately expanded, at routing time. However, this option has no effect when an address is just being verified. The way in which @@ -17946,6 +18008,9 @@ There are a few cases where a &(dnslookup)& router will decline to accept an address; if such a router is expected to handle "all remaining non-local domains", then it is important to set &%no_more%&. +The router will defer rather than decline if the domain +is found in the &%fail_defer_domains%& router option. + Reasons for a &(dnslookup)& router to decline currently include: .ilist The domain does not exist in DNS @@ -18024,27 +18089,16 @@ when there is a DNS lookup error. -.option dnssec_request_domains dnslookup "domain list&!!" unset -.cindex "MX record" "security" -.cindex "DNSSEC" "MX lookup" -.cindex "security" "MX lookup" -.cindex "DNS" "DNSSEC" -DNS lookups for domains matching &%dnssec_request_domains%& will be done with -the dnssec request bit set. -This applies to all of the SRV, MX A6, AAAA, A lookup sequence. - - - -.option dnssec_require_domains dnslookup "domain list&!!" unset -.cindex "MX record" "security" -.cindex "DNSSEC" "MX lookup" -.cindex "security" "MX lookup" -.cindex "DNS" "DNSSEC" -DNS lookups for domains matching &%dnssec_request_domains%& will be done with -the dnssec request bit set. Any returns not having the Authenticated Data bit -(AD bit) set wil be ignored and logged as a host-lookup failure. -This applies to all of the SRV, MX A6, AAAA, A lookup sequence. +.option fail_defer_domains dnslookup "domain list&!!" unset +.cindex "MX record" "not found" +DNS lookups for domains matching &%fail_defer_domains%& +which find no matching record will cause the router to defer +rather than the default behaviour of decline. +This maybe be useful for queueing messages for a newly created +domain while the DNS configuration is not ready. +However, it will result in any message with mistyped domains +also being queued. .option mx_domains dnslookup "domain list&!!" unset @@ -19015,10 +19069,12 @@ However, there are some private options which define transports for delivery to files and pipes, and for generating autoreplies. See the &%file_transport%&, &%pipe_transport%& and &%reply_transport%& descriptions below. +.new If success DSNs have been requested .cindex "DSN" "success" .cindex "Delivery Status Notification" "success" redirection triggers one and the DSN options are not passed any further. +.wen @@ -20212,7 +20268,10 @@ value that the router supplies, and also overriding any value associated with .option headers_add transports list&!! unset .cindex "header lines" "adding in transport" .cindex "transport" "header lines; adding" -This option specifies a list of text headers, newline-separated, +This option specifies a list of text headers, +.new +newline-separated (by default, changeable in the usual way), +.wen which are (separately) expanded and added to the header portion of a message as it is transported, as described in section &<>&. Additional header lines can also be specified by @@ -20237,7 +20296,10 @@ checked, since this option does not automatically suppress them. .option headers_remove transports list&!! unset .cindex "header lines" "removing" .cindex "transport" "header lines; removing" -This option specifies a list of header names, colon-separated; +This option specifies a list of header names, +.new +colon-separated (by default, changeable in the usual way); +.wen these headers are omitted from the message as it is transported, as described in section &<>&. Header removal can also be specified by routers. @@ -22962,7 +23024,7 @@ details. .cindex "DNS" "DNSSEC" DNS lookups for domains matching &%dnssec_request_domains%& will be done with the dnssec request bit set. -This applies to all of the SRV, MX A6, AAAA, A lookup sequence. +This applies to all of the SRV, MX, AAAA, A lookup sequence. @@ -22974,7 +23036,7 @@ This applies to all of the SRV, MX A6, AAAA, A lookup sequence. DNS lookups for domains matching &%dnssec_request_domains%& will be done with the dnssec request bit set. Any returns not having the Authenticated Data bit (AD bit) set wil be ignored and logged as a host-lookup failure. -This applies to all of the SRV, MX A6, AAAA, A lookup sequence. +This applies to all of the SRV, MX, AAAA, A lookup sequence. @@ -23125,12 +23187,13 @@ that matches this list, even if the server host advertises PIPELINING support. Exim will not try to start a TLS session when delivering to any host that matches this list. See chapter &<>& for details of TLS. -.option hosts_verify_avoid_tls smtp "host list&!!" * +.new +.option hosts_verify_avoid_tls smtp "host list&!!" unset .cindex "TLS" "avoiding for certain hosts" Exim will not try to start a TLS session for a verify callout, or when delivering in cutthrough mode, to any host that matches this list. -Note that the default is to not use TLS. +.wen .option hosts_max_try smtp integer 5 @@ -23227,12 +23290,14 @@ connects. If authentication fails, Exim will try to transfer the message unauthenticated. See also &%hosts_require_auth%&, and chapter &<>& for details of authentication. +.new .option hosts_try_prdr smtp "host list&!!" * .cindex "PRDR" "enabling, optional in client" This option provides a list of servers to which, provided they announce PRDR support, Exim will attempt to negotiate PRDR for multi-recipient messages. The option can usually be left as default. +.wen .option interface smtp "string list&!!" unset .cindex "bind IP address" @@ -23299,9 +23364,11 @@ handling only one domain at a time. This is useful if you want to use &$domain$& in an expansion for the transport, because it is set only when there is a single domain involved in a remote delivery. +.new It is expanded per-address and can depend on any of &$address_data$&, &$domain_data$&, &$local_part_data$&, &$host$&, &$host_address$& and &$host_port$&. +.wen .option port smtp string&!! "see below" .cindex "port" "sending TCP/IP" @@ -23348,7 +23415,9 @@ However, in some dialup environments hosts are assigned a different IP address each time they connect. In this situation the use of the IP address as part of the retry key leads to undesirable behaviour. Setting this option false causes Exim to use only the host name. +.new Since it is expanded it can be made to depend on the host or domain. +.wen .option serialize_hosts smtp "host list&!!" unset @@ -23486,7 +23555,9 @@ unknown state), opens a new one to the same host, and then tries the delivery in clear. +.new .option tls_try_verify_hosts smtp "host list&!!" * +.wen .cindex "TLS" "server certificate verification" .cindex "certificate" "verification of server" This option gives a list of hosts for which, on encrypted connections, @@ -23499,6 +23570,7 @@ The &$tls_out_certificate_verified$& variable is set when certificate verification succeeds. +.new .option tls_verify_cert_hostnames smtp "host list&!!" * .cindex "TLS" "server certificate hostname verification" .cindex "certificate" "verification of server" @@ -23510,8 +23582,10 @@ versus Subject and Subject-Alternate-Name fields. Wildcard names are permitted limited to being the initial component of a 3-or-more component FQDN. There is no equivalent checking on client certificates. +.wen +.new .option tls_verify_certificates smtp string&!! system .cindex "TLS" "server certificate verification" .cindex "certificate" "verification of server" @@ -23530,6 +23604,7 @@ must be specified. The use of a directory for the option value is not avilable for GnuTLS versions preceding 3.3.6 and a single file must be used. +.wen With OpenSSL the certificates specified explicitly @@ -24297,6 +24372,13 @@ A server unexpectedly closed the SMTP connection. There may, of course, legitimate reasons for this (host died, network died), but if it repeats a lot for the same host, it indicates something odd. +.vitem &%lookup%& +A DNS lookup for a host failed. +Note that a &%dnslookup%& router will need to have matched +its &%fail_defer_domains%& option for this retry type to be usable. +Also note that a &%manualroute%& router will probably need +its &%host_find_failed%& option set to &%defer%&. + .vitem &%refused_MX%& A connection to a host obtained from an MX record was refused. @@ -26373,7 +26455,9 @@ apply to all TLS connections. For any host that matches one of these options, Exim requests a certificate as part of the setup of the TLS session. The contents of the certificate are verified by comparing it with a list of expected certificates. +.new These may be the system default set (depending on library version), +.wen an explicit file or, depending on library version, a directory, identified by &%tls_verify_certificates%&. @@ -26536,7 +26620,9 @@ if it requests it. If the server is Exim, it will request a certificate only if If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it specifies a collection of expected server certificates. -These may be the system default set (depeding on library version), +.new +These may be the system default set (depending on library version), +.wen a file or, depnding on liibrary version, a directory, must name a file or, @@ -27045,8 +27131,8 @@ the feature was not requested by the client. .cindex "QUIT, ACL for" The ACL for the SMTP QUIT command is anomalous, in that the outcome of the ACL does not affect the response code to QUIT, which is always 221. Thus, the ACL -does not in fact control any access. For this reason, the only verbs that are -permitted are &%accept%& and &%warn%&. +does not in fact control any access. For this reason, it may only accept +or warn as its final result. This ACL can be used for tasks such as custom logging at the end of an SMTP session. For example, you can use ACL variables in other ACLs to count @@ -27961,14 +28047,18 @@ is what is wanted for subsequent tests. .cindex "cutthrough" "requesting" This option requests delivery be attempted while the item is being received. -The option usable in the RCPT ACL. +The option is usable in the RCPT ACL. If enabled for a message recieved via smtp and routed to an smtp transport, -and the message has only one recipient, +and only one transport, interface, destination host and port combination +is used for all recipients of the message, then the delivery connection is made while the receiving connection is open and data is copied from one to the other. +An attempt to set this option for any recipient but the first +for a mail will be quietly ignored. If a recipient-verify callout connection is subsequently -requested in the same ACL it is held open and used for the data, +requested in the same ACL it is held open and used for +any subsequent receipients and the data, otherwise one is made after the initial RCPT ACL completes. Note that routers are used in verify mode, @@ -27980,12 +28070,13 @@ Headers may be modified by routers (subject to the above) and transports. Cutthrough delivery is not supported via transport-filters or when DKIM signing of outgoing messages is done, because it sends data to the ultimate destination before the entire message has been received from the source. +It is not supported for messages recieved with the SMTP PRDR option in use. Should the ultimate destination system positively accept or reject the mail, a corresponding indication is given to the source system and nothing is queued. If there is a temporary error the item is queued for later delivery in the usual fashion. If the item is successfully delivered in cutthrough mode -the log line is tagged with ">>" rather than "=>" and appears +the delivery log lines are tagged with ">>" rather than "=>" and appear before the acceptance "<=" line. Delivery in this mode avoids the generation of a bounce mail to a @@ -28777,7 +28868,7 @@ verified is redirected to a single address, verification continues with the new address, and in that case, the subsequent value of &$address_data$& is the value for the child address. -.vitem &*verify&~=&~reverse_host_lookup*& +.vitem &*verify&~=&~reverse_host_lookup/*&<&'options'&> .cindex "&%verify%& ACL condition" .cindex "&ACL;" "verifying host reverse lookup" .cindex "host" "verifying reverse lookup" @@ -28788,6 +28879,9 @@ Verification ensures that the host name obtained from a reverse DNS lookup, or one of its aliases, does, when it is itself looked up in the DNS, yield the original IP address. +There is one possible option, &`defer_ok`&. If this is present and a +DNS operation returns a temporary error, the verify condition succeeds. + If this condition is used for a locally generated message (that is, when there is no client host involved), it always succeeds. @@ -30335,10 +30429,14 @@ It supports a &"generic"& interface to scanners called via the shell, and specialized interfaces for &"daemon"& type virus scanners, which are resident in memory and thus are much faster. +.new +A timeout of 2 minutes is applied to a scanner call (by default); +if it expires then a defer action is taken. +.wen .oindex "&%av_scanner%&" -You can set the &%av_scanner%& option in first part of the Exim configuration -file to specify which scanner to use, together with any additional options that +You can set the &%av_scanner%& option in the main part of the configuration +to specify which scanner to use, together with any additional options that are needed. The basic syntax is as follows: .display &`av_scanner = <`&&'scanner-type'&&`>:<`&&'option1'&&`>:<`&&'option2'&&`>:[...]`& @@ -30353,6 +30451,7 @@ The usual list-parsing of the content (see &<>&) applies. The following scanner types are supported in this release: .vlist +.new .vitem &%avast%& .cindex "virus scanners" "avast" This is the scanner daemon of Avast. It has been tested with Avast Core @@ -30384,6 +30483,7 @@ $ socat UNIX:/var/run/avast/scan.sock STDIO: SENSITIVITY PACK .endd +.wen .vitem &%aveserver%& @@ -30402,17 +30502,39 @@ av_scanner = aveserver:/var/run/aveserver This daemon-type scanner is GPL and free. You can get it at &url(http://www.clamav.net/). Some older versions of clamd do not seem to unpack MIME containers, so it used to be recommended to unpack MIME attachments -in the MIME ACL. This no longer believed to be necessary. One option is -required: either the path and name of a UNIX socket file, or a hostname or IP -number, and a port, separated by space, as in the second of these examples: +in the MIME ACL. This is no longer believed to be necessary. + +The options are a list of server specifiers, which may be +a UNIX socket specification, +a TCP socket specification, +or a (global) option. + +A socket specification consists of a space-separated list. +For a Unix socket the first element is a full path for the socket, +for a TCP socket the first element is the IP address +and the second a port number, +Any further elements are per-server (non-global) options. +These per-server options are supported: +.code +retry= Retry on connect fail +.endd + +The &`retry`& option specifies a time after which a single retry for +a failed connect is made. The default is to not retry. + +If a Unix socket file is specified, only one server is supported. + +Examples: .code av_scanner = clamd:/opt/clamd/socket av_scanner = clamd:192.0.2.3 1234 av_scanner = clamd:192.0.2.3 1234:local +av_scanner = clamd:192.0.2.3 1234 retry=10s av_scanner = clamd:192.0.2.3 1234 : 192.0.2.4 1234 .endd -If the value of av_scanner points to a UNIX socket file or contains the local -keyword, then the ClamAV interface will pass a filename containing the data +If the value of av_scanner points to a UNIX socket file or contains the +&`local`& +option, then the ClamAV interface will pass a filename containing the data to be scanned, which will should normally result in less I/O happening and be more efficient. Normally in the TCP case, the data is streamed to ClamAV as Exim does not assume that there is a common filesystem with the remote host. @@ -30577,7 +30699,10 @@ which case each use of the &%malware%& condition causes a new scan of the message. The &%malware%& condition takes a right-hand argument that is expanded before -use. It can then be one of +.new +use and taken as a list, slash-separated by default. +.wen +The first element can then be one of .ilist &"true"&, &"*"&, or &"1"&, in which case the message is scanned for viruses. @@ -30590,11 +30715,25 @@ the condition fails immediately. A regular expression, in which case the message is scanned for viruses. The condition succeeds if a virus is found and its name matches the regular expression. This allows you to take special actions on certain types of virus. +.new +Note that &"/"& characters in the RE must be doubled due to the list-processing, +unless the separator is changed (in the usual way). +.wen .endlist -You can append &`/defer_ok`& to the &%malware%& condition to accept messages -even if there is a problem with the virus scanner. Otherwise, such a problem -causes the ACL to defer. +You can append a &`defer_ok`& element to the &%malware%& argument list to accept +messages even if there is a problem with the virus scanner. +Otherwise, such a problem causes the ACL to defer. + +.new +You can append a &`tmo=`& element to the &%malware%& argument list to +specify a non-default timeout. The default is two minutes. +For example: +.code +malware = * / defer_ok / tmo=10s +.endd +A timeout causes the ACL to defer. +.wen .vindex "&$malware_name$&" When a virus is found, the condition sets up an expansion variable called @@ -30638,14 +30777,22 @@ deny message = This message contains malware ($malware_name) .endd -.section "Scanning with SpamAssassin" "SECTscanspamass" +.section "Scanning with SpamAssassin and Rspamd" "SECTscanspamass" .cindex "content scanning" "for spam" .cindex "spam scanning" .cindex "SpamAssassin" +.cindex "Rspamd" The &%spam%& ACL condition calls SpamAssassin's &%spamd%& daemon to get a spam -score and a report for the message. You can get SpamAssassin at -&url(http://www.spamassassin.org), or, if you have a working Perl -installation, you can use CPAN by running: +score and a report for the message. +.new +Support is also provided for Rspamd. + +For more information about installation and configuration of SpamAssassin or +Rspamd refer to their respective websites at +&url(http://spamassassin.apache.org) and &url(http://www.rspamd.com) +.wen + +SpamAssassin can be installed with CPAN by running: .code perl -MCPAN -e 'install Mail::SpamAssassin' .endd @@ -30654,36 +30801,90 @@ documentation to see how you can tweak it. The default installation should work nicely, however. .oindex "&%spamd_address%&" -After having installed and configured SpamAssassin, start the &%spamd%& daemon. -By default, it listens on 127.0.0.1, TCP port 783. If you use another host or -port for &%spamd%&, you must set the &%spamd_address%& option in the global -part of the Exim configuration as follows (example): +By default, SpamAssassin listens on 127.0.0.1, TCP port 783 and if you +intend to use an instance running on the local host you do not need to set +&%spamd_address%&. If you intend to use another host or port for SpamAssassin, +you must set the &%spamd_address%& option in the global part of the Exim +configuration as follows (example): .code spamd_address = 192.168.99.45 387 .endd -You do not need to set this option if you use the default. As of version 2.60, -&%spamd%& also supports communication over UNIX sockets. If you want to use -these, supply &%spamd_address%& with an absolute file name instead of a -address/port pair: + +.new +To use Rspamd (which by default listens on all local addresses +on TCP port 11333) +you should add &%variant=rspamd%& after the address/port pair, for example: +.code +spamd_address = 127.0.0.1 11333 variant=rspamd +.endd +.wen + +As of version 2.60, &%SpamAssassin%& also supports communication over UNIX +sockets. If you want to us these, supply &%spamd_address%& with an absolute +file name instead of an address/port pair: .code spamd_address = /var/run/spamd_socket .endd You can have multiple &%spamd%& servers to improve scalability. These can reside on other hardware reachable over the network. To specify multiple &%spamd%& servers, put multiple address/port pairs in the &%spamd_address%& -option, separated with colons: +option, separated with colons (the separator can be changed in the usual way): .code spamd_address = 192.168.2.10 783 : \ 192.168.2.11 783 : \ 192.168.2.12 783 .endd -Up to 32 &%spamd%& servers are supported. The servers are queried in a random -fashion. When a server fails to respond to the connection attempt, all other +Up to 32 &%spamd%& servers are supported. +When a server fails to respond to the connection attempt, all other servers are tried until one succeeds. If no server responds, the &%spam%& condition defers. -&*Warning*&: It is not possible to use the UNIX socket connection method with -multiple &%spamd%& servers. +.new +Unix and TCP socket specifications may be mixed in any order. +Each element of the list is a list itself, space-separated by default +and changeable in the usual way. + +For TCP socket specifications a host name or IP (v4 or v6, but +subject to list-separator quoting rules) address can be used, +and the port can be one or a dash-separated pair. +In the latter case, the range is tried in strict order. + +Elements after the first for Unix sockets, or second for TCP socket, +are options. +The supported option are: +.code +pri= Selection priority +weight= Selection bias +time=- Use only between these times of day +retry= Retry on connect fail +tmo= Connection time limit +variant=rspamd Use Rspamd rather than SpamAssassin protocol +.endd + +The &`pri`& option specifies a priority for the server within the list, +higher values being tried first. +The deafult priority is 1. + +The &`weight`& option specifies a selection bias. +Within a priority set +servers are queried in a random fashion, weighted by this value. +The default value for selection bias is 1. + +Time specifications for the &`time`& option are .. +in the local time zone; each element being one or more digits. +Either the seconds or both minutes and seconds, plus the leading &`.`& +characters, may be omitted and will be taken as zero. + +Timeout specifications for the &`retry`& and &`tmo`& options +are the usual Exim time interval standard, eg. &`20s`& or &`1m`&. + +The &`tmo`& option specifies an overall timeout for communication. +The default value is two minutes. + +The &`retry`& option specifies a time after which a single retry for +a failed connect is made. +The default is to not retry. +.wen The &%spamd_address%& variable is expanded before use if it starts with a dollar sign. In this case, the expansion may return a string that is @@ -30700,7 +30901,10 @@ The right-hand side of the &%spam%& condition specifies a name. This is relevant if you have set up multiple SpamAssassin profiles. If you do not want to scan using a specific profile, but rather use the SpamAssassin system-wide default profile, you can scan for an unknown name, or simply use &"nobody"&. -However, you must put something on the right-hand side. +.new +Rspamd does not use this setting. However, you must put something on the +right-hand side. +.wen The name allows you to use per-domain or per-user antispam profiles in principle, but this is not straightforward in practice, because a message may @@ -30708,6 +30912,12 @@ have multiple recipients, not necessarily all in the same domain. Because the &%spam%& condition has to be called from a DATA ACL in order to be able to read the contents of the message, the variables &$local_part$& and &$domain$& are not set. +Careful enforcement of single-recipient messages +(eg. by responding with defer in the recipient ACL for all recipients +after the first), +or the use of PRDR, +.cindex "PRDR" "use for per-user SpamAssassin profiles" +are needed to use this feature. The right-hand side of the &%spam%& condition is expanded before being used, so you can put lookups or conditions there. When the right-hand side evaluates to @@ -30754,6 +30964,14 @@ headers, since MUAs can match on such strings. .vitem &$spam_report$& A multiline text table, containing the full SpamAssassin report for the message. Useful for inclusion in headers or reject messages. + +.new +.vitem &$spam_action$& +For SpamAssassin either 'reject' or 'no action' depending on the +spam score versus threshold. +For Rspamd, the recommended action. +.wen + .endlist The &%spam%& condition caches its results unless expansion in @@ -30939,7 +31157,8 @@ containing the decoded data. This is perhaps the most important of the MIME variables. It contains a proposed filename for an attachment, if one was found in either the &'Content-Type:'& or &'Content-Disposition:'& headers. The filename will be -RFC2047 decoded, but no additional sanity checks are done. If no filename was +RFC2047 or RFC2231 decoded, but no additional sanity checks are done. + If no filename was found, this variable contains the empty string. .vitem &$mime_is_coverletter$& @@ -33537,8 +33756,10 @@ failing addresses with their error messages. The third item is used to introduce any text from pipe transports that is to be returned to the sender. It is omitted if there is no such text. .next +.new The fourth, fifth and sixth items will be ignored and may be empty. The fields exist for back-compatibility +.wen .endlist The default state (&%bounce_message_file%& unset) is equivalent to the @@ -34876,8 +35097,8 @@ selection marked by asterisks: &`*etrn `& ETRN commands &`*host_lookup_failed `& as it says &` ident_timeout `& timeout for ident connection -&` incoming_interface `& incoming interface on <= lines -&` incoming_port `& incoming port on <= lines +&` incoming_interface `& local interface on <= and => lines +&` incoming_port `& remote port on <= lines &`*lost_incoming_connection `& as it says (includes timeouts) &` outgoing_port `& add remote port to => lines &`*queue_run `& start and end queue runs @@ -34901,7 +35122,9 @@ selection marked by asterisks: &` smtp_protocol_error `& SMTP protocol errors &` smtp_syntax_error `& SMTP syntax errors &` subject `& contents of &'Subject:'& on <= lines +.new &`*tls_certificate_verified `& certificate verification status +.wen &`*tls_cipher `& TLS cipher suite on <= and => lines &` tls_peerdn `& TLS peer DN on <= and => lines &` tls_sni `& TLS SNI on <= lines @@ -34994,12 +35217,16 @@ routing email addresses, but it does apply to &"byname"& lookups. client's ident port times out. .next .cindex "log" "incoming interface" +.cindex "log" "local interface" +.cindex "log" "local address and port" +.cindex "TCP/IP" "logging local address and port" .cindex "interface" "logging" &%incoming_interface%&: The interface on which a message was received is added to the &"<="& line as an IP address in square brackets, tagged by I= and followed by a colon and the port number. The local interface and port are also -added to other SMTP log lines, for example &"SMTP connection from"&, and to -rejection lines. +added to other SMTP log lines, for example &"SMTP connection from"& and to +rejection lines +and (despite the name) the local interface is added to &"=>"& lines.. .next .cindex "log" "incoming remote port" .cindex "port" "logging remote" @@ -35486,6 +35713,8 @@ search term. If the location of a &'zcat'& command is known from the definition of ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it. +If the ZCAT_COMMAND is not executable, &'exigrep'& tries to use +autodetection of some well known compression extensions. .section "Selecting messages by various criteria (exipick)" "SECTexipick"